Écrin: Gem Cutting

Crystals that grew deep underground for tens of thousands of years, polished to brilliance by your own hands. Écrin is a quiet gem-cutting game: crack a geode, take out the rough stone, and cut it into a jewel.

• Crack a geode Tap the rocky shell a few times and it breaks open to reveal a rough crystal. From diamond, ruby and emerald to Paraíba tourmaline, alexandrite and ammolite, 90 kinds of gemstones are waiting inside.

• Cut it on a faceting machine A 96-tooth index wheel and an angle scale, just like a real faceting machine. Lower the stone onto the spinning lap and grind and polish it one facet at a time. Follow the guide step by step and even your first stone will come out beautifully cut.

• 51 cuts from around the world Round brilliant, emerald, princess, Asscher, rose, briolette and more: 45 named flat-faceted cuts, plus 6 rounded ones such as the cabochon, the buff top and the sphere. For a rounded cut, the stone rolls on the lap as you grind it into a smooth dome with no edges. The same stone sparkles completely differently depending on the cut.

• Chase the light Each stone has its own refractive index and dispersion, and the light passing through it is traced to draw it. Turn the stone with your finger to watch the rainbow fire under the table and the flashes that run across the facets.

• Collection Every stone you crack, cut and finish is kept in your collection, with the cut you chose for it. Pick one up and admire it any time. Sort them by color, hardness, the order you found them and more.

• Requests Every day a customer comes to the workshop looking for a gem. A Nihonga painter wants a stone the color of a painting, a carpenter wants a hard stone for the family of a newly finished house, and a ballet dancer wants earrings light enough to spin in. Listen, choose a stone that fits, cut it and hand it over. Completing requests raises your artisan level and unlocks rare cuts with many steps, such as the briolette, the Jubilee and the Portuguese cut.

• Encyclopedia Look up the color, transparency, hardness, refractive index, specific gravity, birthstone month and origins of all 90 gemstones, including ones you don't own yet. Use it to tell similar stones apart and to find the right one for a request.

• Gem fortune-telling Roll the gems you've collected in your hand, then toss them onto a brass board to read today's fortune. The board is split into five areas: love, work and study, money, rest, and relationships. Where each stone comes to rest decides its reading and its star rating. Throw 1 to 5 of your own gems, once a day.

No account needed. Just open the app and start cutting.